Sheet post-processing apparatus and image forming apparatus using the same

Abstract

A sheet post-processing apparatus includes a first unit having a guide device for guiding a sheet, a second unit having a first post-processing device for performing post-processing on the sheet, and a third unit having a second post-processing device for loading sheets and performing post-processing on the sheets in bunch form placed on the processing tray. A first coupling device is provided for coupling the first unit and at least one of the second and third units. A second coupling device is provided for coupling the second unit and the third unit. The second unit and the third unit are capable of being pulled out in the sheet carrying-out direction with respect to the first unit by releasing the first coupling device. The entire or front side of the second unit is shiftable to the first unit side with respect to the third unit by releasing the second coupling device.

What is claimed is: 
     
       1. A sheet post-processing apparatus comprising:
 a first unit provided with guide means for guiding a sheet that is sequentially carried in; 
 a second unit provided with first post-processing means for performing post-processing to punch and stamp on the sheet that is sequentially carried out of the first unit; and 
 a third unit provided with a processing tray to load sheets that are sequentially carried out through the second unit, second post-processing means for performing post-processing including width alignment, staple binding and adhesive binding on the sheets in bunch form placed on the processing tray, and a collection tray disposed on the downstream side of the processing tray to store the sheets subjected to the post-processing, 
 wherein the first, second and third units are successively provided parallel in a sheet carrying-out direction, 
 the apparatus further has first coupling means for coupling the first unit and at least one of the second unit and third unit, second coupling means for coupling the second unit and the third unit, and shift inhibiting means for inhibiting shift of the second unit to a first unit side due to release of the second coupling means, 
 the second unit and the third unit are capable of being pulled out in the sheet carrying-out direction with respect to the first unit by releasing the first coupling means, 
 the entire or front side of the second unit is capable of shifting to the first unit side with respect to the third unit by releasing the second coupling means, and 
 the apparatus reserves clearance opened widely between the first unit and the second unit located in a pull-out position, 
 the second unit and the third unit are pulled out in the sheet carrying-out direction by releasing the first coupling means, 
 the second unit and the third unit are stopped in pull-out positions by the shift inhibiting means, and 
 the entire or front side of the second unit released by the second coupling means is capable of shifting to the first unit side after releasing inhibition of the shift inhibiting means. 
 
     
     
       2. The sheet post-processing apparatus according to  claim 1 , wherein the guide means of the first unit is comprised of a pair of guide plates for guiding frontside and backside of the carried-in sheet, and a pair of transport rollers that are supported by the pair of guide plates to be mutually rotatable and that nip and transport the carried-in sheet, and
 a guide plate on the second unit side of the pair of guide plates is opened in conjunction with inhibition release of the shift inhibiting means so as to release a nip of the pair of transport rollers. 
 
     
     
       3. The sheet post-processing apparatus according to  claim 1 , wherein the second unit and the third unit are supported to be movable by a pair of front and back guide rails provided in parallel with each other in the sheet carrying-out direction, and the second unit separates parallel from the third unit by releasing the second coupling means. 
     
     
       4. The sheet post-processing apparatus according to  claim 1 , wherein the second unit and the third unit are mutually supported on their rear side swingably by a hinge mechanism, the second unit is supported on its front side by a lock mechanism to be capable of being coupled/released to/from the third unit, and one of the second unit and the third unit is provided with releasing means for releasing coupling of the lock mechanism. 
     
     
       5. The sheet post-processing apparatus according to  claim 4 , wherein the shift inhibiting means inhibits open on the front side of the second unit to the first unit side due to coupling release of the second coupling means, and
 the second unit and the third unit are held in pull-out positions by the shift inhibiting means, and open on the front side of the second unit coupling-released by the second coupling means is capable of being created after releasing hold of the shift inhibiting means. 
 
     
     
       6. The sheet post-processing apparatus according to  claim 4 , wherein the first post-processing means is a punching apparatus, and by opening the front side of the second unit to the first unit side, storage space is provided which enables a punching waste box to be installed in a substantially center portion of the inclined punching apparatus, from the downstream side in the sheet carrying-out direction and the front side. 
     
     
       7. The sheet post-processing apparatus according to  claim 6 , the shift inhibiting means inhibits open on the front side of the second unit to the first unit side due to coupling release of the second coupling means, open on the front side of the second unit coupling-released by the second coupling means is created by releasing hold of the shift inhibiting means, and the punching waste box is removed from the storage space. 
     
     
       8. The sheet post-processing apparatus according to  claim 7 , wherein the second post-processing means is a stapler apparatus comprised of a main body of a stapler and a staple storing portion detachable from the main body, the stapler apparatus has a shift mechanism that shifts to the front side of the apparatus by a replenishment signal (end, near end, manual) of staples of the staple storing portion, and with the front side of the second unit coupling-released by the second coupling means opened widely by releasing hold of the shift inhibiting means, the staple storing portion of the stapler apparatus is capable of being removed from the opened front side. 
     
     
       9. The sheet post-processing apparatus according to  claim 1 , wherein the first unit is provided with sheet transport means having a sheet transport roller pair comprised of a driving roller and a driven roller that are capable of coming into press-contact and separating with/from each other on the upstream side in a sheet transport direction for transporting the sheet, and sheet allocating means for allocating the sheet to a post-processing transport path or a switchback transport path at a branch point for branching the post-processing transport path for guiding the sheet to the post-processing section on the downstream side in the sheet transport direction, and the switchback transport path for receiving the sheet which is fed from a sheet carry-in entrance by the forward/backward rotation roller and is returned by switchback, and control means having first control means for switching the allocating means to the post-processing transport path side while bringing the sheet transport roller pair into press-contact, and second control means for switching the allocating means to the switchback transport path side while separating the sheet transport roller pair. 
     
     
       10. The sheet post-processing apparatus according to  claim 9 , further comprising:
 a forward/backward rotation motor that rotates forward and backward by the control means; 
 rotation direction converting means for converting both forward rotation and backward rotation of driving means into a rotation direction for rotating the driving roller in the sheet transport direction; and 
 driving means in which the first control means rotates the forward/backward rotation motor forward to switch the allocating means to the post-processing transport path side, while bringing the sheet transport roller pair into press-contact to rotate the driving roller in the sheet transport direction, and the second control means rotates the forward/backward rotation motor backward to switch the allocating means to the switchback transport path side, while separating the sheet transport roller pair to rotate the driving roller in the sheet transport direction. 
 
     
     
       11. The sheet post-processing apparatus according to  claim 10 , wherein the rotation direction converting means is comprised of two one-way clutches coupled to the rotary shaft that supports the driving roller of the sheet transport roller pair and the forward/backward rotation motor to drive, and
 the two one-way clutches are configured so that when the forward/backward rotation motor rotates forward, one of the clutches conveys the rotation to the rotary shaft to drive and rotate the driving roller in the sheet carrying-out direction, while the other clutch idles, and that when the forward/backward rotation motor rotates backward, one of the clutches idles, while the other clutch conveys the rotation to the rotary shaft to drive and rotate the driving roller in the sheet carrying-out direction. 
 
     
     
       12. The sheet post-processing apparatus according to  claim 10 , wherein the driving means is provided with a coupling mechanism for coupling the allocating means for switching the sheet to the switchback transport path side and the forward/backward rotation motor to drive, and
 the coupling mechanism is comprised of a one-way clutch that idles by forward rotation of the forward/backward rotation motor, while being driven by backward rotation of the forward/backward rotation motor, 
 a strike member and a torque limiter that regulate a swing range of the one-way clutch being driven by backward rotation of the forward/backward rotation motor, 
 cam means for slaving by rotation of the one-way clutch, and 
 a swing lever that swings by the cam means to drive the allocating means. 
 
     
     
       13. The sheet post-processing apparatus according to  claim 9 , wherein the coupling means separates the driven roller from the driving roller by backward rotation of the forward/backward rotation motor. 
     
     
       14. The sheet post-processing apparatus according to  claim 1 , wherein the first unit is provided with sheet transport means having a sheet transport roller pair comprised of a driving roller and a driven roller that are capable of coming into press-contact and separating with/from each other on the upstream side in a sheet transport direction for transporting the sheet, a first branch point for branching a post-processing transport path for feeding the sheet to the post-processing section on the downstream side in the sheet transport direction, and a non-post-processing transport path for discharging the sheet without feeding to the post-processing section, a second branch point for branching the non-post-processing transport path and a switchback transport path for receiving the sheet which is fed from a sheet carry-in entrance by the forward/backward rotation roller and is returned by switchback, and sheet allocating means comprised of first allocating means provided at the first branch point to allocate the sheet to the post-processing transport path and the non-post-processing transport path, and second allocating means provided at the second branch point to allocate the sheet to the non-post-processing transport path and the switchback transport path, and
 control means having first control means for switching the allocating means to the post-processing transport path side while bringing the sheet transport roller pair into press-contact, and second control means for switching the allocating means to the switchback transport path side while separating the sheet transport roller pair. 
 
     
     
       15. An image forming apparatus comprising:
 a main body of the image forming apparatus provided with a paper feed section that sequentially feeds sheets on a stacker, a printing section that performs predetermined print on a sheet from the paper feed section, a fusing section that heats and fuses ink on the sheet fed from the printing section, and a sheet discharge section that sequentially carries the sheet from the fusing section out of a sheet discharge outlet; 
 an image reading apparatus that is disposed above the main body of the image forming apparatus to read an original image set on a platen; and 
 a sheet post-processing apparatus comprised of a first unit provided with guide means for guiding the sheet that is sequentially carried in from the main body of image forming apparatus, a second unit provided with first post-processing means for performing post-processing to punch and stamp on the sheet that is sequentially carried out of the first unit, and a third unit provided with a processing tray to load sheets that are sequentially carried out through the second unit, second post-processing means for performing post-processing including width alignment, staple binding and adhesive binding on the sheets in bunch form placed on the processing tray, and a collection tray disposed on the downstream side of the processing tray to store the sheets subjected to the post-processing, 
 wherein the first, second and third units are successively provided parallel in a sheet carrying-out direction, the sheet post-processing apparatus further has first coupling means for coupling the first unit and at least one of the second unit and third unit, and second coupling means for coupling the second unit and the third unit, the second unit and the third unit are capable of being pulled out in the sheet carrying-out direction with respect to the first unit by releasing the first coupling means, and the entire or front side of the second unit shifts to the first unit side with respect to the third unit by releasing the second coupling means, 
 the sheet post-processing apparatus reserves clearance opened widely between the first unit and the second unit located in a pull-out position, and has shift inhibiting means for inhibiting open on the front side of the second unit to the first unit side due to release of the second coupling means, 
 the second unit and the third unit are pulled out in the sheet carrying-out direction by releasing the first coupling means, 
 the second unit and the third unit are stopped in pull-out positions by the shift inhibiting means, and 
 the entire or front side of the second unit released by the second coupling means shifts to the first unit side after releasing inhibition of the shift inhibiting means. 
 
     
     
       16. The image forming apparatus according to  claim 15 , wherein an original reading section is disposed above the main body of the apparatus, the paper feed section is disposed below the main body of the apparatus, the printing section is disposed between the original reading section and the paper feed section, the sheet post-processing apparatus provided with a sheet discharge section is disposed in a space portion of the main body of the apparatus formed by the original reading section, the printing section and the paper feed section, a transport path exit of a switchback transport path for two-side printing is formed on the top face of the sheet post-processing apparatus, it is configured that in two-side printing, a sheet with printing on its one side is drawn back again after a transport front end portion of the sheet is sent to the top face of a sheet post-processing section from the transport path exit so as to undergo switchback transport, and
 the first unit is provided with sheet transport means having a sheet transport roller pair comprised of a driving roller and a driven roller that are capable of coming into press-contact and separating with/from each other on the upstream side in a sheet transport direction for transporting the sheet, and sheet allocating means for allocating the sheet to a post-processing transport path or a switchback transport path at a branch point for branching the post-processing transport path for guiding the sheet to the post-processing section on the downstream side in the sheet transport direction, and the switchback transport path for receiving the sheet which is fed from a sheet carry-in entrance by the forward/backward rotation roller and is returned by switchback, and control means having first control means for switching the allocating means to the post-processing transport path side while bringing the sheet transport roller pair into press-contact, and second control means for switching the allocating means to the switchback transport path side while separating the sheet transport roller pair. 
 
     
     
       17. A sheet post-processing apparatus comprising:
 a first unit provided with guide means for guiding a sheet that is sequentially carried in; 
 a second unit provided with first post-processing means for performing post-processing to punch and stamp on the sheet that is sequentially carried out of the first unit; and 
 a third unit provided with a processing tray to load sheets that are sequentially carried out through the second unit, second post-processing means for performing post-processing including width alignment, staple binding and adhesive binding on the sheets in bunch form placed on the processing tray, and a collection tray disposed on the downstream side of the processing tray to store the sheets subjected to the post-processing, 
 wherein the first, second and third units are successively provided parallel in a sheet carrying-out direction, 
 the apparatus further has first coupling means for coupling the first unit and at least one of the second unit and third unit, and second coupling means for coupling the second unit and the third unit, 
 the second unit and the third unit are capable of being pulled out in the sheet carrying-out direction with respect to the first unit by releasing the first coupling means, 
 the entire or front side of the second unit is capable of shifting to the first unit side with respect to the third unit by releasing the second coupling means, and 
 the second unit and the third unit are supported to be movable by a pair of front and back guide rails provided in parallel with each other in the sheet carrying-out direction, and the second unit separates parallel from the third unit by releasing the second coupling means. 
 
     
     
       18. A sheet post-processing apparatus comprising:
 a first unit provided with guide means for guiding a sheet that is sequentially carried in; 
 a second unit provided with first post-processing means for performing post-processing to punch and stamp on the sheet that is sequentially carried out of the first unit; and 
 a third unit provided with a processing tray to load sheets that are sequentially carried out through the second unit, second post-processing means for performing post-processing including width alignment, staple binding and adhesive binding on the sheets in bunch form placed on the processing tray, and a collection tray disposed on the downstream side of the processing tray to store the sheets subjected to the post-processing, 
 wherein the first, second and third units are successively provided parallel in a sheet carrying-out direction, 
 the apparatus further has first coupling means for coupling the first unit and at least one of the second unit and third unit, and second coupling means for coupling the second unit and the third unit, 
 the second unit and the third unit are capable of being pulled out in the sheet carrying-out direction with respect to the first unit by releasing the first coupling means, 
 the entire or front side of the second unit is capable of shifting to the first unit side with respect to the third unit by releasing the second coupling means, and 
 the second unit and the third unit are mutually supported on their rear side swingably by a hinge mechanism, the second unit is supported on its front side by a lock mechanism to be capable of being coupled/released to/from the third unit, and one of the second unit and the third unit is provided with releasing means for releasing coupling of the lock mechanism. 
 
     
     
       19. An image forming apparatus comprising:
 a main body of the image forming apparatus provided with a paper feed section that sequentially feeds sheets on a stacker, a printing section that performs predetermined print on a sheet from the paper feed section, a fusing section that heats and fuses ink on the sheet fed from the printing section, and a sheet discharge section that sequentially carries the sheet from the fusing section out of a sheet discharge outlet; 
 an image reading apparatus that is disposed above the main body of the image forming apparatus to read an original image set on a platen; and 
 a sheet post-processing apparatus comprised of a first unit provided with guide means for guiding the sheet that is sequentially carried in from the main body of image forming apparatus, a second unit provided with first post-processing means for performing post-processing to punch and stamp on the sheet that is sequentially carried out of the first unit, and a third unit provided with a processing tray to load sheets that are sequentially carried out through the second unit, second post-processing means for performing post-processing including width alignment, staple binding and adhesive binding on the sheets in bunch form placed on the processing tray, and a collection tray disposed on the downstream side of the processing tray to store the sheets subjected to the post-processing, 
 wherein the first, second and third units are successively provided parallel in a sheet carrying-out direction, the sheet post-processing apparatus further has first coupling means for coupling the first unit and at least one of the second unit and third unit, and second coupling means for coupling the second unit and the third unit, the second unit and the third unit are capable of being pulled out in the sheet carrying-out direction with respect to the first unit by releasing the first coupling means, and the entire or front side of the second unit shifts to the first unit side with respect to the third unit by releasing the second coupling means, 
 wherein the second unit and the third unit are supported to be movable by a pair of front and back guide rails provided in parallel with each other in the sheet carrying-out direction, and the second unit separates parallel from the third unit by releasing the second coupling means. 
 
     
     
       20. An image forming apparatus comprising:
 a main body of the image forming apparatus provided with a paper feed section that sequentially feeds sheets on a stacker, a printing section that performs predetermined print on a sheet from the paper feed section, a fusing section that heats and fuses ink on the sheet fed from the printing section, and a sheet discharge section that sequentially carries the sheet from the fusing section out of a sheet discharge outlet; 
 an image reading apparatus that is disposed above the main body of the image forming apparatus to read an original image set on a platen; and 
 a sheet post-processing apparatus comprised of a first unit provided with guide means for guiding the sheet that is sequentially carried in from the main body of image forming apparatus, a second unit provided with first post-processing means for performing post-processing to punch and stamp on the sheet that is sequentially carried out of the first unit, and a third unit provided with a processing tray to load sheets that are sequentially carried out through the second unit, second post-processing means for performing post-processing including width alignment, staple binding and adhesive binding on the sheets in bunch form placed on the processing tray, and a collection tray disposed on the downstream side of the processing tray to store the sheets subjected to the post-processing, 
 wherein the first, second and third units are successively provided parallel in a sheet carrying-out direction, the sheet post-processing apparatus further has first coupling means for coupling the first unit and at least one of the second unit and third unit, and second coupling means for coupling the second unit and the third unit, the second unit and the third unit are capable of being pulled out in the sheet carrying-out direction with respect to the first unit by releasing the first coupling means, and the entire or front side of the second unit shifts to the first unit side with respect to the third unit by releasing the second coupling means, and 
 the second unit and the third unit are mutually supported on their rear side swingably by a hinge mechanism, the second unit is supported on its front side by a lock mechanism to be capable of being coupled/released to/from the third unit, and one of the second unit and the third unit is provided with releasing means for releasing coupling of the lock mechanism.